Oki Electric Industry Co., Ltd.

Yokogawa Electric Corporation

Takashi Tsubota

Akishige Ito

Yasumasa Kashima

Masao Kobayashi

Yoshinori Matsumoto

Yoji Hosoi

Masato Ishikawa

Toyoaki Hamaguchi

A photoelectric conversion element evaluation apparatus includes: a probe light source that irradiates a photoelectric conversion element as the object of measurement with probe light; a pump light source that irradiates the photoelectric conversion element being irradiated with the probe light with pulsed pump light; and a light receiving element that detects time dependency of a change in an amount of the probe light obtained from the photoelectric conversion element.

Photoelectric conversion element evaluation apparatus

An inspection apparatus using polarized lights according to one aspect of the present invention includes an irradiator configured to irradiate an inspection target with a first plurality of lights. The first plurality of lights have different polarization states and different wavelengths from each other. The inspection apparatus further includes a light receiver configured to perform a wavelength demultiplexing of a second plurality of lights obtained from the inspection target to generate a third plurality of lights, to separately receive the third plurality of lights, and to output at least one light-receiving signal associated with the third plurality of lights and a processor configured to calculate at least one of an ellipse azimuth, a degree of polarization, and a polarization component intensity using the light-receiving signal and to determine whether the inspection target is defective or non-defective.

Inspection apparatus using polarized lights

A semiconductor laser emits light through a front end and a rear end, the front end being coupled to an application system. The front end has a higher reflectivity than the rear end, to reduce problems caused by returning light. More light is therefore emitted through the rear end than through the front end. In a light source, the light emitted through the rear end is monitored by an optical detector coupled to a control circuit, which controls the voltage applied to the semiconductor laser.

Semiconductor laser and light source

In an opto-semiconductor device, a light-emitting part formed on a substrate, a transparent insulating monocrystalline layer is formed over the entire surface of the substrate covering the light-emitting part, a contact window is opened through the transparent insulating monocrystalline layer in the center of the light-emitting part, and an electrode is formed of a transparent conductive monocrystalline layer passing through the contact window and connected to the central part of the light-emitting part, the electrode being formed on the transparent insulating monocrystalline layer. A transparent insulating monocrystalline layer may additionally be formed on the device including the electrode formed of the transparent conductive monocrystalline layer, and a photo-sensitive device formed of a monocrystalline layer may be provided on the transparent insulating monocrystalline layer.

Opto-semiconductor device and method of fabrication of the same

A laser diode comprises a substrate, a first blocking layer having a groove, an alternate combination of a lower cladding layer and a second blocking layer, an active layer formed in the groove, and an upper cladding layer. A light-amplifying region and a light-absorbing region are formed alternately in the waveguide. Both regions are disposed periodically at a period corresponding to bragg wavelength.

Laser diode

A superluminescent diode has an active layer confined in a channel cut into current blocking layers on a semiconductor substrate. This structure gives a small output beam diameter and high coupling efficiency, even when coupled into single-mode fiber. At the end of the channel distant from the output facet, the active layer makes slanting contact with a rough diffusing surface formed by the current blocking layers and substrate. This easily-manufactured diffusing surface reduces optical gain within the active layer, thereby preventing lasing without requiring an antireflection coating.

Superluminescent diode

An LED includes a semiconductor substrate, a first blocking layer formed on this semiconductor substrate, a second blocking layer formed on this first blocking layer, a first V-channel extending from the second blocking layer to the semiconductor substrate, and a stripe-geometry light-emitting region formed in the first V-channel. Light is emitted from the LED from one edge of the light-emitting region due to a flow of current in the light-emitting region, to which the current is confined by the blocking layers. The LED also comprises a second V-channel disposed at a certain distance from the other edge of the light-emitting region, on the optical path of the light emitted from this other edge, and an absorbing region is formed in the second V-channel. This absorbing region absorbs the light emitted from the other edge of the light-emitting region. The LED has excellent characteristics in which a stable output of spontaneously-emitted light can be obtained under a wide variety of operating conditions.

Growing community of inventors

Tokyo, Japan

Takashi Tsubota